1. Field of the Invention
The present invention relates to a cellular phone in which a folder can be opened and closed both automatically and manually. In particular, the present invention relates to a folder operating apparatus for a cellular phone which can stably open and close a folder by compensating for the phase difference caused by the instability and the load of the folder operating apparatus by controlling the position of the folder.
2. Description of the Prior Art
Generally, a cellular phone (including personal communication services) is a mobile terminal through which a mobile communication service is provided within a predetermined service area where a portion of subscriber lines regionally fixed is wireless. While the existing communication service is provided through telephone lines installed in fixed places, a cellular phone makes telephone calls possible according to logical private numbers without limit to telephone lines or places.
Since such a cellular phone is easy to carry and convenient in use, the demand therefor is explosively increasing, and to satisfy consumers"" diverse desires, it has become small-sized and multi-functional.
Typically, the cellular phone is classified into three types according to its shape. That is, a bar type having numeral (functional) buttons exposed on the outside, a flip type having a cover for covering the numeral (functional) buttons, and a folder type the body of which is folded by half. With the trend of miniaturization, the folder type cellular phone has been increasingly spread.
FIG. 1 is a perspective view of a conventional folder type cellular phone.
The conventional folder type cellular phone 100 is briefly composed of a body 110 and a folder 120. The body 110 includes numeral (functional) buttons, a microphone, various kinds of built-in signal transmitting/receiving components, and a battery pack mounted thereon for power supply.
The folder 120 includes a display window for displaying various kinds of call information and function information, a speaker, and various kinds of built-in components.
In the folder type cellular phone 100, one side of the folder 120 is connected to the body 110 by a hinge means, and the folder is opened/closed by rotating it in a forward or backward direction around the hinge means.
Specifically, opening and closing of the folder 120 of the cellular phone 100 is performed by the construction illustrated in FIG. 2.
A coil spring 112 which is an elastic member is fixed to a covered end portion of a hollow cylindrical housing 111 integrally formed on the folder 120, and to one side of the coil spring 112, i.e., to an open end portion of the housing 111 is fixed a male coupler 113 having a tapered portion formed on one side thereof so that the portion thereof is projected.
Also, on one side of the body 110 is formed a female coupler 114. On one end portion of the female coupler 114 is formed a connection part 115 connected to the folder 120 through the open end of the housing 111, and the other end portion of the female coupler 114 has a tapered recess for receiving therein the tapered, i.e., projected portion of the male coupler 113. The tapered portions of the male coupler 113 and the female coupler 114 are engaged together to fit each other.
The male coupler 113 and the female coupler 114 serve as a hinge shaft. When the folder 120 rotates, the male coupler 113 also rotates, but the rotation of the female coupler 114 is limited by a fixing hole of a fixing part formed on the body 110. However, if the male coupler 113 rotates over a predetermined angle, the male coupler 113 is pushed backward, compressing the coil spring as shown in FIG. 3.
Accordingly, in case of opening the folder 120, if the rotating angle of the male coupler 113 interlocked with the folder 120 is smaller than the taper angle between the male coupler 113 and the female coupler 114, the folder 120 returns to its original position and is kept in a closed state by the elastic force of the coil spring 112 acting between the male coupler 113 and the female coupler 114. If the rotating angle of the male coupler 113 interlocked with the folder 120 is larger than the taper angle, the male coupler 113 rotates by about 180xc2x0, and is re-engaged with the female coupler 114 to effect the opening of the folder 120.
Meanwhile, in case of closing the folder 120, if the rotating angle of the male coupler 113 is smaller than the taper angle between the male coupler 113 and the female coupler 114, the folder 120 maintains its open state by the returning force of the coil spring 112. If the rotating angle of the male coupler 113 is larger than the taper angle, the male coupler 113 rapidly rotates from a predetermined angle, and the tapered portions of the male coupler 113 and the female coupler 114 are re-engaged together to close the folder 120.
However, the conventional folder type cellular phone 100 as above has a disadvantage that since the folder 120 is somewhat heavy, a user should open the folder 120 with one hand in a state that the body 110 is held by the other hand.
In order to solve this problem, a cellular phone having an operating device for automatically opening/closing the folder 120 has been recently proposed.
According to this cellular phone, the folder 120 is automatically opened/closed by manipulating a switch with one hand to drive the operating device. Here, the most important matter to be considered is that it should be possible to operate the folder 120 manually as well as automatically.
FIG. 4 is a sectional view illustrating a main part of a cellular phone having an operating device installed in a housing.
Referring to FIG. 4, the driving device includes a motor 116 elastically supported by the coil spring, and a gear box 117 connected to the shaft of the motor 116.
The motor 116 operates by a switch manipulated by the user, and generates a driving force for a time period determined by a timer.
The gear box 117 is connected to the shaft of the motor 116 to reduce the rotating speed of the motor and to prevent the reverse rotation thereof. The output shaft of the gear box is connected to the male coupler 113 which is selectively engaged with the opposite female coupler 114.
If the switch is manipulated to automatically open the folder 120, the male coupler 113 and the female coupler 114 are fixedly engaged together, and the body 110 of the motor 116 rotates around the shaft. This makes the folder 120 having the housing 111 in which the motor 116 is fixedly installed also rotate for a predetermined time, and thus the folder is in an open state from the body 110.
On the contrary, if the switch is re-manipulated to close the folder 120, the body 110 of the motor 116 rotates in a reverse direction centering around the shaft, and this makes the folder 120 also rotate in a reverse direction and be in a close state.
Meanwhile, if the folder 120 rotates in a forward or backward direction from the body 110 by the user to manually open or close the folder 120, a slip is produced between the male coupler 113 and the female coupler 114, and the male coupler 113 compresses the coil spring 112 with the motor 116 to cause a displacement therebetween, so that the folder 120 rotates.
Then, if the folder 120 reach a predetermined position, the male coupler 113 returns to its original position by the elastic supporting force of the coil spring 112, and is re-engaged with the female coupler 114, so that the folder 120 is rapidly opened or closed.
According to the conventional folder type cellular phone, however, since the motor 116 for rotating the folder 120 operates for the time period determined by the timer, the folder 120 may not reach a complete open position/close position determined for complete opening/closing of the folder 120 in the event that the output characteristic, i.e., RPM of the motor 116 is changed.
Also, if the folder 120 is held by the hand during the automatic opening/closing of the folder 120, or if an external force acts on the folder 120 due to a faulty manipulation of the switch in a state that the cellular phone is pocketed, the male coupler 113 stops at any position, not the complete open/close position.
This causes the folder 120 not to be opened/closed completely or to be open over a predetermined open angle of 150xc2x0 in a manual operation mode.
Therefore, an object of the invention is to provide a folder operating apparatus for a cellular phone, which can achieve a stable opening and closing of the folder by compensating for the phase difference caused by the alternation of automatic and manual operations of the folder or caused by the change of the output characteristic of a power generating means.
In accordance with the present invention, the above object is accomplished by providing a folder operating apparatus for a cellular phone comprising: a rotating section provided in a folder and having driving means for generating a driving force; a fixing section, connected to a body, for rotatably supporting the body at both sides of the rotating section; a power transferring section provided with a pair of members connected to the driving means and the fixing section, and selectively engaged together to face each other; an elastic means for applying to the power transferring section a supporting force greater than a driving torque of the driving means, and being elastically compressed so that the power transferring section is separated therefrom when an external force is applied to the folder; and position detecting means, installed at corresponding positions of the rotating section and the power transferring section, for controlling the driving means when the rotating section and the power transferring section are in a same-phase state.